1. Technical Field
The present disclosure relates to friction members and camera shutters and, in particular, to a friction member used for a brake mechanism and a camera shutter using the same.
2. Discussion of Related Art
In order to obtain a camera shutter with high shutter speed and high durability, it is important to make shutter blades light and to improve the brake performance of a brake mechanism of the shutter.
The braking force of the brake mechanism varies according to the thickness of friction members such as washers, and a set of friction members having proper thickness to calibrate the braking force. Polyethylene terephthalate (PET) is often used as a material of the friction members. However, the friction members made of PET can be damaged by the blade in the braking process with an acceleration of the shutter speed. Thus, the initial braking performance cannot be maintained, and the shutter blade can be damaged in an early stage, or the durability of the shutter may be extremely decreased.
What is needed, therefore, is to provide a friction member for brake mechanism and a camera shutter using the same that can overcome the above-described shortcomings.